1. Field of the Invention
This invention relates to building wall construction and, more particularly, to channel header and footer beams and matching studs.
2. Prior Art
Interior wall construction using horizontal channel beams as headers and footers and matching vertical studs received into the channel beams is well-known. Commonly, the studs are also channel-shaped and both are made of metal, typically steel.
An advantage of steel wall construction is the strength of the wall and ease of assembly, the studs snapping into place in the beam within a retaining device in the beam. A screw between the beam and the stud then secures them together. U.S. Pat. Nos. 4,854,096 and 4,805,364 by Smolik represents such construction. Smolik shows his retaining device as a portion of the beam bent over at selected positions to hold a stud therebetween or the entire end of a beam flange bent over and slotted to receive a stud in the slot. The stud is then urged into place as the beam slightly spreads and the stud slightly closes, resiliently springing back into original form as the stud slips into place. Disassembly is also an advantage as the stud can be removed from the beam about as easy as it is slipped into place.
Another advantage of steel wall construction is that it provides a strong interior nonbearing wall that can be configured to allow building movement such as during a seismic event without damage to the wall. Paquette (U.S. Pat. No. 5,127,203) and Brady (U.S. Pat. No. 5,127,760) describe a beam with slots in each beam flange. A building stud is placed in the beam at a slot and a screw is inserted through the slot and into the stud. Thus, upon movement of the building, the studs can slide vertically in the beam as the screws slide in the beam slots. The allowed vertical movement of the beams is clearly limited to the length of the slot as the screw is constrained to slide within it. Resistance to lateral movement of the studs in the beam is by the shear strength in the screws and what further construction might be on the wall, such as wallboard. Each screw must be precisely installed by a tradesman who is in a hurry. The screw must not be too tight that it binds and prevents the sliding motion for which it was designed. It also must not deform the beam which would need to be repaired before use so that a channel wall can tolerate movement during a seismic event, or building expansion or contraction. It must also not be loose such that it prevents wall board installation over it. It is preferred that the wall be configured so studs can slide in the beam without screws that can require additional labor and careful attention on installation.
Vertical alignment of studs is typically done manually during construction with a stud connected between a footer beam and a header beam. Screws generally are employed to hold a metal stud in the metal footer and header beams. It is preferable to use simple channel beams as either the footer or the header beam and use beams with stud-retaining devices as the other beam only. It would be preferable also to avoid the labor cost of manually aligning each stud vertically or aligning a header beam with a footer beam when both employ beams that receive a building stud in a defined position in the beam. To do so, the beam should have an inherent alignment device incorporated so during construction a stud is aligned perpendicular to the beam as its first end is installed in the beam independent of another beam to which the other stud end may or may not be installed. In this way, a simple beam can be employed, for example, as a footer beam while the stud-aligning beam can be used as header beam. If that header beam also allowed the building stud to slide within the beam, it also could allow for building movement, expansion and contraction. If the stud sliding in the beam were not limited, except of course by the reach of the beam flanges, then the stud in beam wall construction could accommodate a larger range of movement than that allowed in the screws in slots approach.
It is therefore an object of the present invention to provide a channel beam that can be implemented as either a footer or a header beam that inherently aligns a building stud in a single beam perpendicular to the beam during assembly of the stud in the beam. Thus, a second aligning beam becomes unnecessary.
It is also an object that the stud be slidable in the beam without limits of movement imposed by slots or other restrictive means. It is another object that while the stud is free to move vertically in the beam, lateral movement of the stud in the beam is substantially impeded beyond that provided by screws, or entirely without screws, that must be precisely installed. It is a further object that the walls have a capability of a fire rating of at least one hour.
These primary objects are achieved in a channel beam comprising a plurality of chutes of rectangular cross-section, the chutes perpendicular to the beam for receiving a plurality of matching generally-rectangular building studs in unrestricted sliding relation within the chute. (Actually, metal studs are C-shaped with one side generally open. However, that generally open side also includes opposing lips in the plane of the side sandwiching the open area. These lips suffice for purposes of aligning the stud in the beam. Therefore, for purposes of descriptions following, the metal building stud with a generally-open side will be considered effectively closed with the lips providing necessary contacts for aligning the stud in the chute). The chute comprises two or more vertical alignment guides on each chute side aligned on a line normal to the beam web.
Opposing beam flanges perpendicular to the beam web on each side of the web may comprise chute alignment guides for two chute sides (a continuous side or line being equivalent in the limit to an infinite number of vertical guides). The other two opposing chute sides comprise at least two chute guides projecting from the beam flanges, usually connected at their distal ends for added strength and stability against lateral movement of the building stud. Each beam flange generally has a pair of these vertically-aligned guides providing redundant alignment to the studs.
A further definition of the chute may comprise rims extending from distal ends of beam flanges, slotted in alignment with flange slots with flange slots and rim slots bordering and defining chutes to receive studs therein. With two border points provided by the flange ridges, the flange rim provides a third defining border point to the chute and further enhances the flange rigidity and resistance to stud lateral movement.
In an alternative embodiment, the chute may comprise projections outward of the beam channel sized to receive a building stud or a tongue extending from the stud and running longitudinally along opposing stud sides.
In practice, a chuted beam of the present invention may be employed as a header in which case the stud is urged into the chute laterally as the beam and stud slightly stretch and bend until the stud snaps into place in the chute in vertical relation to the horizontal beam. To accommodate movement in the building, the stud is free to slide vertically in the beam chute but typically rests on a footer beam. This footer beam may be a simple channel beam without alignment or retaining devices because the stud is already vertically aligned by the header beam. The only limit to vertical stud movement is the extent of the chute which can be of arbitrary design length limited only by the size of the beam flanges which can be formed as large as desired.
With a horizontal wall board member on each side of a minor channel extension from the beam web adapted to receive anchors countersunk therein and a vertical wall board with an end sandwiched between each beam flange and a vertical beam panel parallel to the flange, the desired fire rating is achieved. In another embodiment, the desired fire rating is achieved by blowing noncombustible material into the beam between the beam web and stud ends positioned in the beam and spaced apart from the beam web. Gypsum wall board is then secured to the studs outside of the beam flange such that the flange is sandwiched between the studs and the wall board with board ends extending beyond the stud ends in the direction of the beam web. Thus, the wall board overlaps the noncombustible material in the beam to complete fire barrier. The studs with wall board attached are disposed to slide in the beam a distance measured between the wall board ends and the structure to which the beam web is anchored. As the studs slide in the beam, the stud comprising sides without a closed end cuts into the noncombustible material to create a slit imaging the stud with width that of each stud walls. Thus, the noncombustible material remains effectively undisturbed from possible stud movement during building shifting or a seismic event.
In another embodiment assuring a fire barrier, wall board is secured to the studs which together slide within the beam as an integral unit. Again, noncombustible material is blown into the beam between the beam web and stud ends positioned in the beam and spaced apart from the beam web. A first lip extends outward from the beam web past the flange. A matching second lip extends from the intermediate the flange, or even at the flange distal end creating a groove therebetween at a position overlapping the stud with wall board. Combustible material is inserted into the groove thus creating a wall barrier of desired thickness in the groove that overlaps the wallboard attached to the studs.
In still another embodiment, a first wall board member is attached outside the beam flange. A second wall board member is attached to the wall stud in vertical alignment with the first wall board member with ends of the first and second wall board members spaced apart to form a gap to allow the wall stud to slide within the beam channel without the wall board members impacting. A third wall board member overlaps the gap, attached either to the first wall board member creating a downward-opening groove in which the second wall board member slides, or to the second wall board member creating a upward-opening groove in which the first wall board member slides. The wall stud within the beam channel may included side slots through which screws attaching the first wall board member passes and in which the screw slides as the stud moves in the beam.